Cafeteria video sent to FBI for analysis

LITTLETON, Colorado (CNN) -- Three young men taken in for questioning after they showed up outside Columbine High School during last week's massacre have been cleared of any involvement in the school shooting, according to the Jefferson County Sheriff's's Department.

Earlier, Mark Paulter, Jefferson County's chief deputy district attorney, told CNN that surveillance videotapes from the school captured a "very chaotic" scene as Eric Harris, 18, and Dylan Klebold, 17, hurled homemade bombs and opened fire on terrified students in the cafeteria.

Nine students remained hospitalized Wednesday.

Authorities previously had not said whether the tapes contained any useful images. The tapes were sent to an FBI lab in Quantico, Virginia, for a frame-by-frame enhancement and analysis.

During a late night news conference on Tuesday, Jefferson County Sheriff John Stone said authorities found discrepancies in the information provided by three unarmed young men in dark jackets and combat-style boots who were frisked and taken off for interrogation after they were spotted in a field near the school.

He also said the three young men were able to name the gunmen before their names had been released. Stone said one of the trio had been expelled from Columbine High.

Investigators tested them for gun residue after the shootings and found no evidence that they had fired guns, Paulter said.

Jefferson County Sheriff's Department spokesman Steve Davis said Wednesday
that the three men have been cleared of any involvement in the school shooting.

Stone said that Harris and Klebold initially tried to escape through three separate exits in the school, and killed themselves only after being turned back by police gunfire each time.

Investigators have questioned Klebold's 18-year-old girlfriend, who police say bought at least two weapons used by Klebold and Harris in the attack. Investigators want to know whether she knew how the guns were to be used. Authorities describe her as a witness, not a suspect.

Stone said police gunfire prevented Harris and Klebold
from fleeing the school through three separate exits

Meanwhile, Marine Corps officials said Harris had tried to enlist but was told during a home visit from a recruiter on April 15 -- five days before the massacre -- that he had been rejected for medical reasons.

The Marines refused to discuss the medical reason, but a Harris family friend, Victor Good, told The New York Times that the teen had been taking psychiatric medicine -- a potentially disqualifying factor -- and was seeing a psychiatrist.

A spokesman for the Marine Corps Recruiting Command in Virginia told CNN that any recruit under a doctor's care for virtually any reason would be disqualified for service.